Some image forming apparatuses such as copying machines and multifunction printers display, in accordance with image data processed according to the type of document and the setting conditions (e.g., print density, enlarging/reducing ratio, single-side printing/duplex printing, margin size), a preview of a single image to be printed or a combination of images to be printed.
Such a preview display is described, for example, in Patent Literature 1, which discloses a technique for generating a preview image without performing edge enhancement on image data. This technique prevents a high-frequency component near the sampling frequency of an image display device from being so amplified that only the moiré of a preview image is enhanced and the preview image therefore looks obviously different from an image to be outputted as a hard copy.